A separatist leader declared Monday that eastern Ukraine's Donetsk region was not only independent, but also would ask to join Russia -- a day after referendum organizers claim voters in the region chose to break away from Kiev.

Denis Pushilin, self-declared leader of the Donetsk People's Republic, told a crowd that no further referendum was needed to ask Russia to annex it.

Pro-Russian separatists held a referendum Sunday asking residents of the Donetsk region whether it should declare independence from Ukraine. Nearly 90% of voters in the area favored secession, an election official said Monday.

A similar question was put to voters in Luhansk. Preliminary results were expected Monday, officials said.

But a new poll for CNN suggests that support for alliance with Russia is much weaker than pro-Russian separatists say, even in the east.

Just over a third (37%) of Ukrainians in three eastern regions favor an alliance with Russia, while 14% of the region backs an alliance with the European Union and about half (49%) say Ukraine would be better off if it did not ally with either, the poll found.

"Eastern Ukraine" includes the regions of Donetsk, Luhansk and Kharkiv.

Neither Ukraine's government nor the European Union immediately reacted to Pushilin's overture to Russia, though both dismissed Sunday's votes.

"This propagandist farce will not have any legal consequences, only criminal responsibility of its organizers," acting Ukrainian President Oleksandr Turchynov said in a statement Monday.

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"That farce the terrorists call a referendum is nothing else but a propagandist cover for killings, kidnapping, violence and other grave crimes," he said.

He reiterated that his government will continue fighting against "terrorists, saboteurs and criminals" but will negotiate with those in eastern Ukraine "who do not have blood on their hands and those who are ready to defend their goals and beliefs in a legal way."

A vote for autonomy is a vote for the self-destruction of the east, Turchynov has said.

It would cut residents off from the national economy and social programs, he said. "It is a step (to) nowhere for these regions. It is euphoria that may lead to very complex consequences, and many people can already feel them."

Pushilin's announcement is reminiscent of separatists' moves in the Black Sea peninsula of Crimea, which Russia annexed after Crimeans voted to secede from Ukraine and join Russia in a March 16 referendum.

The CNN findings come from a poll by the agency ComRes of 1,000 adult Ukrainians contacted by telephone in Russian and Ukrainian between May 7-11. Three percent said they didn't know. The poll's margin of error is 3.1 percentage points.

Reactions from Russia, NATO, European Union

Russia welcomed Sunday's votes.

"Moscow respects the will of the population of the Donetsk and Luhansk regions, and hopes that the practical implementation of the outcome of the referendums will proceed along civilized lines, without repeat outbreaks of violence," the Kremlin said in a statement.

The referendum was "organized in a chaotic manner with dubious and ambiguous questions," he said, adding that the only "thing that counts" is Ukraine's planned presidential election on May 25.

"I urge all actors to make sure that those general elections can be conducted in an orderly manner," Rasmussen said.

He said that he feels NATO and its allies have sent a "very clear message to Moscow" and assured its allies. Recently, U.S. Army forces have been deployed to Poland and three Baltic states. Amanpour challenged Rasmussen, asking him whether he thought that was enough to demonstrate "heft."

Rasmussen responded that NATO is "considering further steps."

"Those further steps might include an update of existing defense plans, development of new defense plans, enhanced exercises and also appropriate deployment," he said.

It's too early, he said, to describe anything more specifically, "but we will not hesitate to take further steps if needed," he said.

German Chancellor Angela Merkel also described the referendum as illegitimate and said the focus should be on the May 25 presidential election in Ukraine.

Meanwhile, the European Union imposed sanctions related to the Ukraine crisis on another 13 people, bringing the total number to 61, an EU diplomat said Monday.

Details about the sanctions given to the 13 weren't immediately available, but previously announced sanctions included asset freezes and visa bans.

The diplomat did not name the newly sanctioned people or reveal their nationalities. Previous targets included Dmitry Kozak, Russia's deputy prime minister; Valery Gerasimov, Russia's military chief; and pro-Russian separatists in Ukraine, including Pushilin.

The EU also has imposed sanctions on two entities in Crimea, the diplomat said Monday.

Merkel and French President Francois Hollande have warned that Russia could face more consequences if the Ukrainian presidential vote does not go ahead as planned.

"If no internationally recognized presidential election were to take place, this would inevitably further destabilize the country," Merkel said.

In that case, she said, "we are ready to take further sanctions against Russia."

Merkel and Hollande also said that Russian troops along the Ukrainian border "should undertake visible steps to reduce their readiness."

Putin announced a troop pullback Wednesday, but NATO says it has seen no signs of a withdrawal of Russian forces from the border area.

Russia annexed the southern region of Crimea after announced results in a separatist referendum showed more than 90% in favor of joining Russia. In an independent survey by the Pew Research Center, 54% of Crimea residents showed support for secession.

The Kremlin has said that it has no interest in annexing other parts of Ukraine. But it is pushing for the country to adopt a constitution that would give regions where Russian is widely spoken a larger voice in policy-making.

Critics fear that the creation of autonomous pro-Russian regions in Ukraine would cement alliances with the Kremlin that would give it essential control over them.